Spotify's 'Discover Weekly' mixtapes get some kid brothers

Spotify has always wanted to put all the music in the world at your fingertips. Now it's trying to figure out the best ways to hunt out tracks you actually like.

On Tuesday, Spotify launched Daily Mix. It's a new personalized playlist full of songs Spotify already believes you prefer and peppered with a few unfamiliar but similar tunes.

It's a companion to its popular Monday morning mixtape, Discover Weekly, which surprised even Spotify with its runaway success.

In the rapidly growing format of "all-you-can-eat" streaming music, Spotify is the biggest service by subscribers. The model opens up listeners to a vast catalog tens of millions of songs, but it creates new tangles for companies figuring out how to suit consumers' specific tastes as their listening habits change. A digital download library, packed with music that you already cared about enough to buy, is simple to just shuffle and play. Spotify is trying to figure out how to spin you the sliver of songs you like, without making it feel like work.

Daily Mix, perhaps confusingly, doesn't change every day. Spotify says the name is meant to imply it's for daily listening. Where Discover Weekly is meant to bubble up music that's new to you, Daily Mix is supposed to supply you with old favorites.

Spotify will begin rolling out the new feature out to all mobile users with enough listening history to generate at least one Daily Mix. People with a large library can have up to six different mixes, while most users will have between one and three.

Each mix is loosely arranged around a mood or a genre, and many contain up to 5,000 songs. Spotify won't refresh them daily, but if a listener returns to the Daily Mix after more than eight hours away, the playlist will jumble itself up and start fresh. Spotify said this is supposed to create the impression of "near-endless playback." The company will update the underlying data curating the mix weekly, so it is supposed to change as your tastes shift.

On the flip side, Discover Weekly is a personalized two-hour playlist completely refreshed for each user every Monday, which Spotify launched in July 2015 to unanticipated popularity.

In Discover Weekly's first 10 months, more than 40 million out of Spotify's roughly 100 million users had tried it, and more than half of its listeners come back the following week, the company said in May. In addition, more than half of them stream at least 10 tracks from it each week, tallying up to 5 billion total song streams in the first 10 months.